A reproduction device reproducing image signals from optical disks such as DVD or BD (Blu-ray Disc) is known. In the conventional reproduction device, data are reproduced in block units constituted by data in a plurality of frame units, the reproduction rate of data in block units is controlled, and data in frame units are omitted, from among the data in block units according to the controlled reproduction rate (see, for example, Patent Literature 1).
The reproduction device also outputs the reproduced data, in which some of the data in frame units have been thinned, to an image display device such as a liquid crystal display or a plasma display, and the image display device displays the inputted reproduced data.
By so thinning some of the reproduced data, it is possible to display the data at an apparently high rate.
However, in the conventional image display device, the reproduced data downsampled in frame units in the reproduction device are displayed as they are. For this reason, motion is not accurately reproduced, and the viewer can have a sense of visual discomfort.
FIG. 23 shows an example of the reproduced image signal reproduced by the reproduction device and the downsampled image signal outputted from the reproduction device. FIG. 23 illustrates a case in which one frame image is thinned from among four frame images. FIG. 23 shows how a round image moves as a constant speed from the left to the right on the screen. A frame image F4 is thinned from among the frame images F1 to F6 constituting the reproduced video signal. As a result, the downsampled image signal is constituted by frame images F1 to F3, F5, and F6.
As shown in FIG. 23, when a frame image is divided into a plurality of blocks according to the size of the round image, in the reproduced image signal, the round image moves rightward by one block at a time, but in the downsampled image signal, the round image moves by two blocks between the frame image F3 and the frame image F5 and the motion becomes discontinuous.
Thus, when a frame image is thinned in the reproduction device, the image displayed in the image display device becomes discontinuous, and the viewer can have a sense of visual discomfort.